دراسة تأثير وزن الكتكوت عند عمر يوم واحد على الآداء الإنتاجي والفسيولوجي لطيور اللحم في البيئة الليبية

Study of the effect of chick weight at one day of age on the productive and physiological performance of broiler birds under the Libyan environment

Samira Musbah Ammar ,1  Hatim Ashour Ishrayhah 1,  Ali Ibrahim Ali Jabbr  2  Milad Faraj Alfulit 1, Abdulhakim Abrahim Kamba 1, Guma Masoud Elfelali1,

1-Department of Veterinary Sciences, Higher Institute of Agricultural Technology, Al Ghiran, Tripoli, Libya

2- Department of Agricultural Sciences,  Tawargha high institute of Science and Technology

   Abstract:

This study aims to investigate the impact of broiler chick weight at hatch on productive and physiological performance, with a focus on feed conversion ratio and flock uniformity at 21–42 days of age. The experiment was conducted on a privet farm near of Tripoli. A total of 120 unsexed day-old Ross 308 chicks, sourced from a local company importing fertilized eggs, were used in the study. Several factors, including breeder age, egg storage duration, incubation timing, and chick reception, were standardized. The chicks were weighed and divided into four groups (treatments):Group 1: Chicks weighing between 35–35.9 g (average 35.45 g/bird).Group 2: Chicks weighing between 40–40.9 g (average 40.51 g/bird).Group 3: Chicks weighing between 45–45.9 g (average 45.41 g/bird).Group 4 (Control): Chicks randomly selected with an average weight of 39.35 g/bird. The groups were housed separately in floor pens, divided by iron fences, with each group split into three replicates of 10 birds each. Environmental, nutritional, and veterinary conditions were standardized across all groups. The results revealed significant differences in chick weight at hatch, even when controlling for factors such as breeder age, egg storage duration and chick reception. Additionally, significant differences were observed between Groups 1, 2, and 3 in terms of body weight, weight gain, and feed conversion ratio at 21 and 42 days of age respectively. However, no significant differences were found between Group 2 (40g) and the control group (39g) in terms of live body weight, weight gain or feed conversion ratio. Furthermore, the study showed no significant differences among all groups in the relative weights of vital organs (gizzard, liver, intestines) or edible organs (heart, liver and gizzard) in relation to carcass weight. Similarly, no significant differences were found in blood serum cholesterol and triglyceride levels among the groups. In conclusion the results of this study demonstrate the importance of chick weight at one-day old as heavier chick weights had better vitality higher feed consumption rate, and a better feed conversion ratio compared to lighter chicks.

Kay word: broiler chicken, Initial weight, Growth performance, food consumption